Watching football on Sundays is a whole new experience with NFL Network's channel, NFL RedZone. Find out why.

"You're nervous and anxious for every game," said Koets, who made his first NFL start last week against the Colts as an extra tight end. "Obviously, to get this opportunity, I'm excited. I've been here a long time, and I'm ready to go show what I can do."

O'Hara has not missed a start since the wild-card game in 2007. However, he has been bothered by tendinitis in his left ankle and Achilles' tendon since the team reported to training camp in August.

Koets averaged roughly 50 snaps a game in the preseason so he is used to working with Manning.

O'Hara had his left foot put in a boot on Monday and he has not practiced this week. Coach Tom Coughlin said his availability will be a game-time decision, noting that the 33-year-old is the type of player who doesn't need practice to play.

Koets has spent a lot of time talking to O'Hara this week just in case.

"Being able to play under Shaun and being here this long, I know that he's a great guy to learn from," Koets said. "He knows what he's doing and he's always there to help out. If you have any questions or anything in regards to specifics about what's going on, he's there to help. I'm definitely using that."

Offensive coordinator Kevin Gilbride said he considered a number of ways to replace O'Hara, but noted that using Koets at center would mean there was only one move being made on the line.

Listen to the 2011 NFL season LIVE -- hear all the action online in premium sound quality with NFL Audio Pass. Sign up now!

If he had moved Rich Seubert from guard to center and started Shawn Andrews in his spot, it would have meant two moves.

"I think we felt that Adam has been playing well enough that he deserved the chance to start because, by doing that, we've made less overall changes," Gilbride said. "It's one person, so rather than changing three, you're changing one. If we didn't think he could do the job or he hadn't been playing well when we've asked him to do it, you couldn't make that decision, but he's earned it."

Defensive captain Justin Tuck also missed Friday's workout with a shoulder injury, but insisted he will play.

"It's football," Tuck said. "Every person in this locker room deals with injuries every day. Just got to go get the treatment, go get some ice, stim, and hopefully go out there and play your best game on Sunday."

Tuck said once a player gets on the field, he forgets the injury.

"Oh, you feel limited," he said. "Painwise, you get into that gladiator mode. I don't know how to explain it. You just don't worry about it."

Notes: Coughlin says special teams captain Chase Blackburn is questionable for the game with a right knee injury, and backup safety Michael Johnson is out with a back issue.